Synthesis of MCM-41-type mesoporous materials using filtrate of alkaline dissolution of ZSM-5 zeolite

MCM-41-type mesoporous materials possessing strong Bronsted acidity originated from ZSM-5 zeolite were synthesized by using soluble aluminosilicate species containing the fragments of the structure of ZSM-5 zeolite. The thermal stability of the mesoporous structure of the obtained mesoporous material was enhanced by the post-treatment with an ammonium aqueous solution. These results suggest an important role of alkalinity of slurries on the following two processes; (1) alkaline dissolution of ZSM-5 zeolite and (2) formation of mesoporous structure. These successive processes were efficiently improved by use of a continuous-flow reactor. The mesoporous material synthesized in the continuous-flow reactor catalyzed the cracking of cumene at 523 K, while a conventional Al-MCM-41 hardly catalyzed. The mesoporous material synthesized by using the filtrate of alkaline dissolution of ZSM-5 possessed a stronger Bronsted acidity than a conventional Al-MCM-41. (C) 2004 Elsevier Inc. All rights reserved.